[en] Longitudinal spray distribution is mainly affected by the horizontal speed variations of the nozzles.
Manufacturers classically try to reduce unwanted nozzles movements using horizontal boom
suspension but these methods have performance and price limitations. This paper describes a spray
controller aiming to compensate the effect of the horizontal boom movements on the spray deposits
homogeneity. The controller is based on three main components: a control law describing the relationship
between nozzle speed, nozzle flow and spray deposit; a real time measurement of the boom
horizontal speed variations using micro-machined capacitive accelerometers, and pulse width modulation
(PWM) nozzle flow actuators. To assess the feasibility of such a controller, a single nozzle
prototype was developed and tested in the laboratory, using a nigrosine solution. Spray coverage
was measured using image analysis for field representative nozzle speed variations. The spray coverage
uniformity using the controller showed about 51% compensation of the variations observed
without it.
Al-Gaadi K.A., Ayers P.D. Monitoring controller-based field sprayer performance. Applied Engineering in Agriculture. 10(2):1994;205-208.
Anthonis J., Ramon H., De Baerdemaeker J. Implementation of an active horizontal suspension on a spray boom. Transactions of the ASAE. 43(2):2000;213-220.
Enfält P., Enggvist A., Alness K. Assessment of the dynamic spray distribution on a flat surface using image analysis. Aspects of Applied Biology. 48:1997;17-25.
Frost A.R. Simulation of an active spray boom suspension. Journal of Agricultural Engineering Research. 30:1984;313-325.
Frost A.R., O'Sullivan J.A. Verification and use of a mathematical model of an active twin link boom suspension. Journal of Agricultural Engineering Research. 40:1988;259-274.
Giles D.K., Comino A. Droplet size on spray pattern characteristics of an electronic flow controller for spray nozzle. Journal of Agricultural Engineering Research. 47:1990;249-267.
Lebeau, F., 2003. Modélisation de la répartition dynamique des produits phytopharmaceutiques sous une rampe de pulvérisation (Modelling the distribution of spray deposit of phytopharmaceutical products under a spray boom). Ph.D. Thesis, Gembloux, Faculté universitaire des Sciences agronomiques, 197 pp.
Lebeau, F., Destain, M.-F., 2000. Sensor data fusion for the measurement of horizontal sprayer boom displacement. In: Ramon, H., Hostens, I. (Eds.), Proceedings of the 1st International Workshop on Noise and Vibration in Agricultural and Biological Engineering, ISMA 25, Leuven, pp. 1615-1618.
Nation H.J. The dynamic behaviour of field sprayer booms. Journal of Agricultural Engineering Research. 27:1982;61-70.
Nation H.J. The design and performance of a gimbal-type mounting for sprayer booms. Part 1. Development procedure. Journal of Agricultural Engineering Research. 36:1987a;233-246.
Nation H.J. The design and performance of a gimbal-type mounting for sprayer booms. Part 2. Optimisation model and validation. Journal of Agricultural Engineering Research. 36:1987b;247-260.
Ooms D., Lebeau F., Ruter R., Destain M.-F. Estimation of horizontal displacement of boom sprayer by sensor fusion. Computers and Electronics in Agriculture. 33(2):2002;139-162.
Ooms D., Ruter R., Lebeau F., Destain M.-F. Impact of the horizontal movements of a sprayer boom on the longitudinal spray distribution in field conditions. Crop Protection. 22:2003;813-820.
O'Sullivan J.A. Simulation of the behaviour of a spray boom with an active and passive pendulum suspension. Journal of Agricultural Engineering Research. 35:1986;157-173.
O'Sullivan J.A. Verification of passive and active version of a mathematical model of a pendulum spray boom suspension. Journal of Agricultural Engineering Research. 40:1988;89-101.
